How to work out your real cost per mile (and why guessing it ruins your profit math)

Most gig drivers know their fuel cost. Far fewer know their real cost per mile — and that gap is where profit math quietly goes wrong.

Fuel is only one part. A mile also wears your tyres, brakes, oil, and engine, and it brings the next service closer. If you count fuel alone, every shift looks more profitable than it really was.

Here is a simple way to work out your own number, using your own records rather than anyone else's average:

1. Add up a month of driving costs: fuel, plus what you spent on maintenance, tyres, and servicing in that month. If a big service bill lands once a year, divide it by twelve and count one month's share.
2. Add up the miles you drove for work that month — paid miles and unpaid miles together. Dead miles count, because they wear the car just the same.
3. Divide the total cost by the total miles. That is your cost per mile.

Then use it on every shift: multiply your shift's total miles by that rate, and subtract the result from your gross pay alongside fuel, tolls, parking, and food. What is left is much closer to your real net profit.

One honest warning: this number is an estimate, not a promise. Tyre and service costs arrive in lumps, not evenly, so your monthly figure will move around. Recalculate it every month or two, and treat a single good month with suspicion, not celebration.

The habit matters more than the exact figure. Once you have a cost per mile you trust, two shifts with the same gross pay stop looking equal — the one with more miles and more waiting time is usually the weaker shift, even when the headline pay says otherwise.

ShiftLog is a free Android app that helps gig workers and drivers track each shift's pay, costs, and net profit, offline with no account needed: https://play.google.com/store/apps/details?id=com.shiftlog.app